Negative Autoregulation of the Organizer-specific Homeobox Gene goosecoid*
- From the Forschungszentrum Karlsruhe, Institute of Genetics, P.O. Box 3640, D-76021 Karlsruhe and ‖Department of Cell Biology, Max Planck Institute for Developmental Biology, P.O. Box 2109, D-72011 Tübingen,Federal Republic of Germany
Abstract
The homeobox gene goosecoid has been implicated to play a central role in the Spemann organizer tissue of the vertebrate embryo. Misexpression of goosecoid on the ventral side of a Xenopus laevis gastrula embryo was shown to result in a partial duplication of the primary body axis, reminiscent of the Spemann organizer graft. Normal embryonic development thus requires tight temporal and spatial control of genes instrumental for organizer function. In the present study we investigated the transcriptional control of goosecoid gene expression. Sequence analysis of the mouse and human promoter region revealed the presence of two palindromic binding elements for homeobox genes of the prd type to which goosecoidbelongs. We show that Goosecoid protein can bind to these sitesin vitro. By using reporter gene constructs of the human and mouse promoter, we demonstrate that Goosecoid can act as a repressor of its own promoter activity in transient co-transfection experiments in mouse P19 cells and in Xenopus embryos. Autorepression depends on the presence of the homeodomain and is mediated through the prd element more proximal to the transcriptional start site. Our results suggest a role forgoosecoid in restricting organizer activity in the vertebrate gastrula embryo.
Footnotes
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↵* The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) (cDNA-D), (cDNA-E), (mouse goosecoid promoter), and (human goosecoid promoter).
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↵‡ Recipient of a predoctoral fellowship of the Boehringer Ingelheim Fond.
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↵§ Performed part of this work as a postdoctoral fellow in the lab of Eddy M. De Robertis at UCLA. To whom correspondence should be addressed: Karlsruhe Research Center, Institute of Genetics, P.O. Box 3640, D-76021 Karlsruhe, Germany. Phone: 49-7247-823394; Fax: 49-7247-823354; E-mail: Martin.Blum@IGEN.FZK.DE.
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↵¶ Supported by a grant of the Volkswagen Stiftung.
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↵1 C. Zhu and M. Blum, unpublished observations.
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↵2 The abbreviations used are: BMP, bone morphogenetic protein; CMV, cytomegalovirus; DE, distal element; E, embryonic day (days post-coitum); NF stage, stage of Xenopusembryonic development according to the table of Nieuwkoop and Faber (26); PCR, polymerase chain reaction; PE, proximal element;prd, paired; RACE, rapid amplification of cDNA ends; bp, base pair(s); kb, kilobase pair(s).
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- Received March 14, 1997.
- Revision received September 22, 1997.
- The American Society for Biochemistry and Molecular Biology, Inc.
